SAN DIEGO NATURAL HISTORY MUSEUM BALBOA PARK - SAN DIEGO SOCIETY OF NATURAL HISTORY - ESTABLISHED 1874

Post Office Box 121390 * San Diego, California 92112-1390 * Telephone 619-255-0309 * FAX 619-255-0187 * www.sdnhm.org

10 October 2013 Angela Pham ASM Affiliates, Inc. 2034 Corte Del Nogal Carlsbad, CA 92011 RE: Paleontological Record Search for the SX-PQ project (Project Number 21060) Dear Ms. Pham:

This letter presents the results of a paleontological record search conducted for the SX-PQ project (Project Number 21060). The project alignment begins 1 mile south of Carmel Mountain, 0.8 miles north of Sorrento Valley Boulevard, and 0.7 miles east of Interstate 5. From there the project alignment runs northeast, running north of and parallel to Los Penasquitos Creek for 2.5 miles. The alignment then turns due north for 2 miles, crossing Deer Creek and McGonigle Creek before again angling northeast for another 2.7 miles. Just to the west of Black Mountain, the alignment makes a sharp turn south/southeast for 3.8 miles to Scripps Poway Parkway, and from there trends more gently east/southeast for a final 4 miles. The main project alignment terminates at a substation in the Scripps Ranch Neighborhood of the City of San Diego.

Published geological reports (Kennedy, 1975; Kennedy and Peterson, 1975) that cover the entirety of the project reveal that the proposed project is located in areas underlain by Holocene-age (less than 10,000 years old) undifferentiated alluvium and slopewash, Late Pleistocene-age (0.5 to 1.5 million years old) Lindavista Formation, Late Eocene-age (37 to 42 million years old) Pomerado Conglomerate, Late Eocene-age (approximately 43 million years old) Mission Valley Formation, Middle Eocene-age (44-48 million years old) Stadium Conglomerate, Middle Eocene-age (45 to 46 million years old) Friars Formation, Middle Eocene-age (47 million years old) Scripps Formation, Middle Eocene-age (47 to 48 million years old) Ardath Shale, Late Cretaceous-age (66 to 100 million years old) undifferentiated granitic rocks and gabbro rocks of the southern California batholith, and Late Jurassic/Early Cretaceous-age (120 to 130 million years old) Santiago Peak Volcanics. The rock unit mapped by Kennedy as the Stadium Conglomerate in the Poway and Del Mar quadrangles was later referred by Walsh (1996) and Walsh et al. (1996) to the conglomerate tongue of the Friars Formation.

Site records housed in the Department of Paleontology at the San Diego Natural History Museum document fifty-nine recorded fossil collecting localities (see abbreviated locality descriptions) within a one-quarter-mile buffer zone of the project site (see attached map), with eight of these localities occurring directly within the project alignment boundaries. One locality was discovered in the near-shore marine deposits of the Early Pleistocene-age (approximately 0.5 to 1.5 million years old) Lindavista Formation. This locality produced trace remains of

marine invertebrates (e.g., angelwing bivalve burrow infillings). Three localities were found in the fluvial deposits of the Middle Eocene (approx. 43 million years old) Mission Valley Formation. These localities produced fossilized remains of terrestrial vertebrates (e.g., rodents, marsupials, crocodilians, camels, and primates). Thirty-one localities were discovered in the marine, fluvial, estuarine, and lacustrine deposits of the middle Eocene-age (approximately 45 to 46 million years old) Friars Formation. Recovered fossils include leaf and seed pod impressions of plants (e.g., horsetail, sycamore, sumac, oak, willow, beech, hickory, magnolia, fern, palm, and other flowering plants), impressions and internal molds of freshwater and marine invertebrates (e.g. snails, mussels, oysters, and clams), fossilized remains of marine vertebrates (e.g., sharks, rays, and fish), and fossilized remains of terrestrial vertebrates (e.g., turtles, rodents, lizards, snakes, bats, opossums, insectivores, gliding mammals, artiodactyls, rhinos, crocodilians, brontotheres, and primates). Eleven localities were found in marine deposits of the Eocene-age (approximately 47 million years old) Scripps Formation. These localities produced leaf impressions of flowering plants, trace fossils of marine invertebrates (e.g., bivalve burrows and worm tubes), and the internal and external molds of marine invertebrates (e.g., snails, urchins, slugs, clams, oysters, and tusk shells). Four localities were discovered in the transition zone between the Scripps Formation and the middle Eocene-age (approximately 47-48 million years old) Ardath Shale. These localities produced leaf impressions of plants (e.g., willows), and the shell remains and internal molds of marine invertebrates (e.g., oysters, clams, snails, urchins, and decapods). Seven localities were found in marine deposits of the Ardath Shale. These localities produced leaf impressions of flowering plants, shell remains and internal molds of marine invertebrates (e.g., sponges, bryozoans, corals, urchins, snails, oysters, mussels, clams, shrimp, and tusk shells), and scale impressions of marine vertebrates (e.g., fish). The remaining two localities were found in a pebbly sandstone which belongs to the near-shore marine deposits of the Eocene-age (48 to 49 million years old) Torrey Sandstone. These localities produced shell remains and internal molds of marine invertebrates (e.g., bryozoans, foraminifera, urchins, snails, clams, and oysters), and fossilized teeth of marine vertebrates (e.g., fish and rays).

Deméré and Walsh (1993) have assigned a low paleontological resource sensitivity to the Holocene-age undifferentiated alluvium and slopewash flooring the modern drainages that this project alignment crosses. Additionally, Deméré and Walsh (1993) have assigned a moderate paleontological resource sensitivity to the Lindavista Formation, and high paleontological resource sensitivities to the Pomerado Conglomerate, the Mission Valley Formation, the Friars Formation, the Scripps Formation, and the Ardath Shale. Certain meta-sedimentary layers that interbed with the volcanic rocks of the Santiago Peak Volcanics have been known to produce siliceous microfossils and marine macroinvertebrates (Jones and Miller, 1982), and have therefore been assigned a high paleontological resource sensitivity by Deméré and Walsh (1993). These meta-sedimentary layers are known to crop out within the Santiago Peak Volcanics in the Los Penasquitos Canyon area which this project alignment crosses (Deméré and Walsh, 1993). The remaining bulk of the Santiago Peak Volcanics, and all of the Cretaceous-age granitic and gabbro rocks of the southern California batholith are assigned a zero potential for fossils (Deméré and Walsh, 1993) due to their being formed through the crystallization of magma at significant depth. These assigned paleontological resource sensitivity ratings, combined with the proven fossil occurrences in the immediate project area, suggest that any proposed excavation activities that extend deep enough to encounter previously undisturbed deposits of the Lindavista Formation, the Pomerado Conlglomerate, the Mission Valley Formation, the Friars Formation, the Scripps Formation, the Ardath Shale, or the meta-sedimentary layers of the Santiago Peak

Volcanics have the strong potential to cause negative impacts to paleontological resources preserved in these deposits. For the reasons described above, implementation of a complete paleontological resource mitigation program during construction is strongly recommended.

The information contained within this paleontological record search should be considered private and is the sole property of the San Diego Natural History Museum. Any use or reprocessing of information contained within this document beyond the scope of the SX-PQ project (Project Number 21060) is prohibited.

If you have any questions concerning these findings please feel free to contact me at 619-255-0320 or nanderson@sdnhm.org.

Sincerely,

Nikki Anderson Lead Fossil Preparator Department of PaleoServices

Literature Cited: Deméré, T.A. and Walsh, S.L. 1993. Paleontological Resources, County of San Diego. Prepared

for the San Diego Planning Commission: 1-68. Jones, D.A., and R.H. Miller. 1982. Jurassic fossils from the Santiago Peak Volcanics,

San Diego County, California. In, P.L. Abbott (ed.), Geologic Studies in San Diego. San Diego Association of Geologists, fieldtrip guidebook, pp. 93-103.

Kennedy, M.P. 1975. Geology of the Western San Diego Metropolitan area, California. California Division Mines and Geology Bulletin 200-A:7-39.

Kennedy, M.P. and Peterson, G.L. 1975. Geology of the Eastern San Diego Metropolitan area, California. California Division Mines and Geology Bulletin 200-B:43-56.

Walsh, S.L. 1996. Middle Eocene mammal faunas of San Diego County, California, Pp. 75-119. In, D.R. Prothero and R.J. Emry (eds.). The Terrestrial Eocene-Oligocene Transition in North America. Cambridge University Press.

Walsh, S.L., D.R. Prothero, and D.J. Lundquist. 1996. Stratigraphy and paleomagnatism of the middle Eocene Friars Formation and Poway Group, southwestern San Diego County, California, Pp. 120-154. In, D.R. Prothero and R.J. Emry (eds.). The Terrestrial Eocene-Oligocene Transition in North America. Cambridge University Press.

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Map 1 of 2: SDNHM fossil localities within one-quarter mile of the SX-PQ project (Project Number 21060) (Base maps USGS Topographic Maps of the Poway and Del Mar 7.5' Quadrangles, California).

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Map 2 of 2: SDNHM fossil localities within one-quarter mile of the SX-PQ project (Project Number 21060) (Base map USGS Topographic Map of the Poway 7.5' Quadrangle, California).

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San Diego County

Map Extent

Project Alignment